[erlang-questions] Simple NAT traversal

[eigenfunction]

Hi everybody,
i have an erlang application running behind a nat. Now i have come to
a point where i need to know my public ip. I was thinking about
running a tiny tcp server behind the nat whose sole purpose would be
to send me my public ip. My question is this: isn't there a more
simple alternative? Heck, even if i could determine the public ip of
the NAT device without doing a "backflip" it will be enough for my
case.
Any idea?